diff --git a/scripts/build-aml-prebuilts.sh b/scripts/build-aml-prebuilts.sh
index 4b08ac3..8a5513e 100755
--- a/scripts/build-aml-prebuilts.sh
+++ b/scripts/build-aml-prebuilts.sh
@@ -1,14 +1,24 @@
 #!/bin/bash -e
 
-# This is a wrapper around "m" that builds the given modules in multi-arch mode
-# for all architectures supported by Mainline modules. The make (kati) stage is
-# skipped, so the build targets in the arguments can only be Soong modules or
-# intermediate output files - make targets and normal installed paths are not
-# supported.
+# This script is similar to "m" but builds in --soong-only mode, and handles
+# special cases to make that mode work. All arguments are passed on to
+# build/soong/soong_ui.bash.
 #
-# This script is typically used with "sdk" or "module_export" modules, which
-# Soong will install in $OUT_DIR/soong/mainline-sdks (cf
-# PathForMainlineSdksInstall in android/paths.go).
+# --soong-only bypasses the kati step and hence the make logic that e.g. doesn't
+# handle more than two device architectures. It is particularly intended for use
+# with TARGET_PRODUCT=mainline_sdk to build 'sdk' and 'module_export' Soong
+# modules in TARGET_ARCH_SUITE=mainline_sdk mode so that they get all four
+# device architectures (artifacts get installed in $OUT_DIR/soong/mainline-sdks
+# - cf PathForMainlineSdksInstall in android/paths.go).
+#
+# TODO(b/174315599): Replace this script completely with a 'soong_ui.bash
+# --soong-only' invocation. For now it is still necessary to set up
+# build_number.txt.
+
+if [ ! -e build/soong/soong_ui.bash ]; then
+  echo "$0 must be run from the top of the tree"
+  exit 1
+fi
 
 export OUT_DIR=${OUT_DIR:-out}
 
@@ -23,109 +33,19 @@
   OUT_DIR=${AML_OUT_DIR}
 fi
 
-if [ ! -e "build/envsetup.sh" ]; then
-  echo "$0 must be run from the top of the tree"
-  exit 1
-fi
+mkdir -p ${OUT_DIR}/soong
 
-source build/envsetup.sh
-
-my_get_build_var() {
-  # get_build_var will run Soong in normal in-make mode where it creates
-  # .soong.kati_enabled. That would clobber our real out directory, so we need
-  # to run it in a different one.
-  OUT_DIR=${OUT_DIR}/get_build_var get_build_var "$@"
-}
-
-readonly SOONG_OUT=${OUT_DIR}/soong
-mkdir -p ${SOONG_OUT}
+# The --dumpvars-mode invocation will run Soong in normal make mode where it
+# creates .soong.kati_enabled. That would clobber our real out directory, so we
+# need to use a different OUT_DIR.
+vars="$(OUT_DIR=${OUT_DIR}/dumpvars_mode build/soong/soong_ui.bash \
+        --dumpvars-mode --vars=BUILD_NUMBER)"
+# Assign to a variable and eval that, since bash ignores any error status
+# from the command substitution if it's directly on the eval line.
+eval $vars
 
 # Some Soong build rules may require this, and the failure mode if it's missing
 # is confusing (b/172548608).
-readonly BUILD_NUMBER="$(my_get_build_var BUILD_NUMBER)"
-echo -n ${BUILD_NUMBER} > ${SOONG_OUT}/build_number.txt
+echo -n ${BUILD_NUMBER} > ${OUT_DIR}/soong/build_number.txt
 
-readonly PLATFORM_SDK_VERSION="$(my_get_build_var PLATFORM_SDK_VERSION)"
-readonly PLATFORM_VERSION="$(my_get_build_var PLATFORM_VERSION)"
-PLATFORM_VERSION_ALL_CODENAMES="$(my_get_build_var PLATFORM_VERSION_ALL_CODENAMES)"
-
-# PLATFORM_VERSION_ALL_CODENAMES is a comma separated list like O,P. We need to
-# turn this into ["O","P"].
-PLATFORM_VERSION_ALL_CODENAMES="${PLATFORM_VERSION_ALL_CODENAMES/,/'","'}"
-PLATFORM_VERSION_ALL_CODENAMES="[\"${PLATFORM_VERSION_ALL_CODENAMES}\"]"
-
-# Get the list of missing <uses-library> modules and convert it to a JSON array
-# (quote module names, add comma separator and wrap in brackets).
-MISSING_USES_LIBRARIES="$(my_get_build_var INTERNAL_PLATFORM_MISSING_USES_LIBRARIES)"
-MISSING_USES_LIBRARIES="[$(echo $MISSING_USES_LIBRARIES | sed -e 's/\([^ ]\+\)/\"\1\"/g' -e 's/[ ]\+/, /g')]"
-
-# Logic from build/make/core/goma.mk
-if [ "${USE_GOMA}" = true ]; then
-  if [ -n "${GOMA_DIR}" ]; then
-    goma_dir="${GOMA_DIR}"
-  else
-    goma_dir="${HOME}/goma"
-  fi
-  GOMA_CC="${goma_dir}/gomacc"
-  export CC_WRAPPER="${CC_WRAPPER}${CC_WRAPPER:+ }${GOMA_CC}"
-  export CXX_WRAPPER="${CXX_WRAPPER}${CXX_WRAPPER:+ }${GOMA_CC}"
-  export JAVAC_WRAPPER="${JAVAC_WRAPPER}${JAVAC_WRAPPER:+ }${GOMA_CC}"
-else
-  USE_GOMA=false
-fi
-
-readonly SOONG_VARS=${SOONG_OUT}/soong.variables
-
-# Aml_abis: true
-#   -  This flag configures Soong to compile for all architectures required for
-#      Mainline modules.
-# CrossHost: linux_bionic
-# CrossHostArch: x86_64
-#   -  Enable Bionic on host as ART needs prebuilts for it.
-# VendorVars.art_mdoule.source_build
-#   -  TODO(b/172480615): Change default to false when platform uses ART Module
-#      prebuilts by default.
-cat > ${SOONG_VARS}.new << EOF
-{
-    "BuildNumberFile": "build_number.txt",
-
-    "Platform_version_name": "${PLATFORM_VERSION}",
-    "Platform_sdk_version": ${PLATFORM_SDK_VERSION},
-    "Platform_sdk_codename": "${PLATFORM_VERSION}",
-    "Platform_version_active_codenames": ${PLATFORM_VERSION_ALL_CODENAMES},
-
-    "DeviceName": "generic_arm64",
-    "HostArch": "x86_64",
-    "HostSecondaryArch": "x86",
-    "CrossHost": "linux_bionic",
-    "CrossHostArch": "x86_64",
-    "Aml_abis": true,
-
-    "Allow_missing_dependencies": ${SOONG_ALLOW_MISSING_DEPENDENCIES:-false},
-    "Unbundled_build": ${TARGET_BUILD_UNBUNDLED:-false},
-    "UseGoma": ${USE_GOMA},
-
-    "VendorVars": {
-        "art_module": {
-            "source_build": "${ENABLE_ART_SOURCE_BUILD:-true}"
-        }
-    },
-
-    "MissingUsesLibraries": ${MISSING_USES_LIBRARIES}
-}
-EOF
-
-if [ -f ${SOONG_VARS} ] && cmp -s ${SOONG_VARS} ${SOONG_VARS}.new; then
-  # Don't touch soong.variables if we don't have to, to avoid Soong rebuilding
-  # the ninja file when it isn't necessary.
-  rm ${SOONG_VARS}.new
-else
-  mv ${SOONG_VARS}.new ${SOONG_VARS}
-fi
-
-# We use force building LLVM components flag (even though we actually don't
-# compile them) because we don't have bionic host prebuilts
-# for them.
-export FORCE_BUILD_LLVM_COMPONENTS=true
-
-m --skip-make "$@"
+build/soong/soong_ui.bash --make-mode --soong-only "$@"
diff --git a/scripts/build-mainline-modules.sh b/scripts/build-mainline-modules.sh
index 39c8fba..7d49492 100755
--- a/scripts/build-mainline-modules.sh
+++ b/scripts/build-mainline-modules.sh
@@ -93,11 +93,17 @@
   done
 done
 
+# We use force building LLVM components flag (even though we actually don't
+# compile them) because we don't have bionic host prebuilts
+# for them.
+export FORCE_BUILD_LLVM_COMPONENTS=true
+
 # Create multi-archs SDKs in a different out directory. The multi-arch script
 # uses Soong in --skip-make mode which cannot use the same directory as normal
 # mode with make.
 export OUT_DIR=${OUT_DIR}/aml
-echo_and_run build/soong/scripts/build-aml-prebuilts.sh ${MODULES_SDK_AND_EXPORTS[@]}
+echo_and_run build/soong/scripts/build-aml-prebuilts.sh \
+  TARGET_PRODUCT=mainline_sdk ${MODULES_SDK_AND_EXPORTS[@]}
 
 rm -rf ${DIST_DIR}/mainline-sdks
 echo_and_run cp -R ${OUT_DIR}/soong/mainline-sdks ${DIST_DIR}